Status Quo Report

Data on the current adoption rates of soil health practices are sparse. These data are hard to estimate because adoption of these practices is still minimal, and because many farms already engaged in these practices do not report utilizing these practices. To estimate current adoption rates of soil health practices, we have identified five representative soil health and carbon sequestration practices to establish an estimate for the status quo adoption rate of regenerative agricultural practices at large. These five practices are:

• Cover Crops • Crop Rotation • No Till • Reduced Till • Organic Fertilizer

In this case, organic fertilizer is a proxy for nutrient management. We have data about these five indicators from the 2017 US Agricultural Census. This census provides us with state and national estimates of farm acreage, farm operations, and the number of acres and operations that use specific practices. In the 2017 Census Data, the total number of US farm locations and farm acreage is given below in Table 1.

Total US Farms

Region	Operations	Acres
US Total	2,042,220	900,217,576

Using the 2017 US Agricultural Census, we obtain data on the number of farm operations utilizing a specific practice and the number of farm acres that the practice is utilized on. These data are provided at the national, state, and county levels. We begin with a national level overview, and then dive down into state-by-state analysis. To estimate current adoption percentages, we divide the total number of US farm operations or farmland acres that a practice is utilized on by the total number of US farm operations or farmland acres. We do not have acreage level estimate for the crop rotation practice.

Percent of US Farmland Acres Farmed Using Representative Soil Health Practices. (Crop rotation was omitted, as acreage data are not available.)

From Figure 1 and Figure 2, we can see that these practices are not widely adopted across the US. In general, adoption percentages across operations and acres behave similarly. No-till and reduced-tilling are the most commonly adopted practices. This difference in adoption percent is at least partially driven by the fact that no-till and reduced-till may save money and labor, while cover crops and organic fertilizer require monetary expenditures, especially on larger plots of land. To better understand the variation in adoption percentages, we examine adoption by size of the farm.

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Percent of US Farmland Farmed Using Representative Soil Health Practices, by Farm Size. (Crop rotation was omitted, as acreage data are not available)

Again, from Figure 3 and Figure 4, we see that adoption percentage trends by farm size are very similar when measured as a percent of all US operations, or when measured as a percent of US farmland acres. We can see that as the size of the farm increased up to 2,000 acres, a greater percent of farms adopt no-till and reduced till practices. As farm size increases the cost of tilling increases. Thus, it makes sense to see a rise in adoption of no-till and reduced till practices as farm size increases. The decline in adoption of these practices among large farms of 2,000 or more acres could be driven by the fact that these large farms are corporate mega-farms. We also notice a slight decline in adoption of cover crops as farm size increases. These graphs also explain the difference between operations and acres in adoption percentages of cover crops: smaller operations are more likely to adopt cover crops than larger operations. The decrease in adoption of cover crops as farm size gets larger supports the notion that as practice costs per acre increase, adoption decreases. This may also be reflective of different values and priorities of small vs. large farms.

State Levels

We now turn to a state-by-state analysis focused on differences in adoption rates along two climates: dry/semiarid and moist/humid. We attempt to map states to these categories based on the 2006 IPCC report used for COMET-Planner modeling as seen in Figure 5. We assign states to a single climate, and thus acknowledge this bias in our estimates. A more detailed analysis would more precisely assign regions to these climates. Note that state level estimates do not include data on adoption percent of organic fertilizer.

Broad Climate Categories for the U.S., 2006 IPCC Report

Percent of Operations Adopting Representative Soil Health Practices, by State and Climate. (Organic fertilizer was omitted, as state level data are not available)

Percent of US Farmland Acres Farmed Using Representative Soil Health Practices, by state and climate. (Crop rotation and organic fertilizer are omitted because state level acreage data are not available)

Figure 6 and Figure 7 provide a state-by-state breakdown of adoption percentages for given practices, weighted by either the total number of operations or total number of acres (in thousands) for that state. From these graphs we learn that dry/semiarid climates seem to have large acreage operations, and that most US states are in moist/humid climates. We also see a high degree of variation in adoption of different practices by state. From Figure 6 @ref(fig:state_ops), we see that crop rotation seems to have the least of amount of variation in adoption between states.

It is difficult to draw any conclusions about differences in practice adoption between the two climates from these two graphs. However, we have other ways of representing our data that may allow us to better analyze differences in practice adoption by climate.

One such tool is a plot of the distribution of practice adoption by states. This density plot will tell us what percent of states have a specific adoption rate for each practice.

Probability Distribution of Percent of Operations Adopting a Practice, by State and Climate

From Figure 8 -@ref(fig:state_dens) we can see that the distribution of adoption percentages for crop rotation and no-till practices are roughly the same between dry/semiarid climates and between moist/humid climates. The distribution of adoption percentage for reduced till is similar across both climates, however, dry/semi-arid climates have a bimodal distribution where some states have high adoption percentages. The difference in mean adoption percentage for cover crops could be driven by the difference in average farm size between the two climates.

Estimating Status Quo Carbon Sequestration

For four of these practices (no-till, reduced till, cover crops, and crop rotations) we have estimates for the tons of CO2 equivalent sequestered per acre per year.

Climate	Practice	Equivalent Tons of CO2 Sequestered per Acre per Year
Moist/Humid	No Till	0.34
Dry/Semiarid	No Till	0.39
Moist/Humid	Reduced Till	0.22
Dry/Semiarid	Reduced Till	0.19
Moist/Humid	Crop Rotation	0.24
Dry/Semiarid	Crop Rotation	0.29
Moist/Humid	Cover Crops	0.41
Dry/Semiarid	Cover Crops	0.29

Since we do not have information for the numbers of acres that crop rotation is performed on, we must estimate this figure. Based on our data we see that the adoption percent of no-till and crop rotation are similar. As such, we will use data about no-till practices to derive a weighted average acres per operation estimate that we can impute into our crop rotation data. To estimate tons of equivalent sequestered carbon, we multiply the number of acres a specific practice is performed on by the equivalent tons of CO2 sequestered per acre per year figure in Table 2.

As such, these estimates need to be reviewed and checked. However, assuming they are accurate, from Figure 9, we can see that moist/humid climates sequester more carbon, likely by virtue of having more farmland that soil health practices are adopted on. We also see that the amount of carbon sequestered differs dramatically by practice. This is also likely driven by differences in adoption rates. One other question to consider is: as a percent of total carbon sequestered by climate is there a difference between the two climates?

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From Figure 10 we can see that in dry/semiarid climates crop rotation makes up a much higher percentage of carbon sequestered than in moist/humid climates. Conversely, moist/humid climates seem to sequester more of their carbon through cover crops and reduced till practices. Based on these data we can also estimate average equivalent carbon tons sequestered per operation. We have these data for three of our practices: Cover Crops, No Till, and Reduced Till.

We see that large farms operations sequester many more tons of carbon than small farms do. Using data from Figure 11 we can now estimate the average amount that farmers will get paid for sequestering carbon under various policy proposals. We can estimate this average for three scenarios: 1) the policy does not incentivize any new adoption; 2) policies incentivize adoption uniformly; and 3) polices incentivize adoption differently.